Abstract: A hat-stringer assembly for an aircraft comprises a hat stringer with a first hat-stringer leg, a second hat-stringer leg, a first hat-stringer sidewall, a connecting wall, a second hat-stringer sidewall, and a ventilation opening, extending through the connecting wall. The hat stringer assembly also comprises a fitting, comprising a first channel member in contact with the first hat-stringer sidewall and the first hat-stringer leg. The fitting also comprises a second channel member in contact with the second hat-stringer sidewall and the second hat-stringer leg. The fitting further comprises a web cap, in contact with the first channel member and the second channel member. The web cap comprises a web-cap opening, which is in fluidic communication with the ventilation opening.

Abstract: A vented hat stringer for an aircraft comprises a first hat-stringer leg with a first-hat-stringer-leg surface, a second hat-stringer leg with a second-hat-stringer-leg surface, a first hat-stringer sidewall, a second hat-stringer sidewall, and a hat-stringer connecting wall, comprising a hat-stringer-connecting-wall surface and a virtual hat-stringer-connecting-wall symmetry plane, passing through hat-stringer connecting wall. The vented hat stringer further comprises a ventilation opening, extending through at least one of the first hat-stringer sidewall or the hat-stringer connecting wall, or extending through at least one of the second hat-stringer sidewall or the hat-stringer connecting wall. The ventilation opening defines a ventilation-opening centerline, wherein the ventilation-opening centerline does not coincide with the virtual hat-stringer-connecting-wall symmetry plane.

Abstract: A vented hat stringer for an aircraft comprises a first hat-stringer leg with a first-hat-stringer-leg surface, a second hat-stringer leg with a second-hat-stringer-leg surface, a first hat-stringer sidewall, a second hat-stringer sidewall, and a hat-stringer connecting wall, comprising a hat-stringer-connecting-wall surface and a virtual hat-stringer-connecting-wall symmetry plane, passing through hat-stringer connecting wall. The vented hat stringer further comprises a ventilation opening, extending through at least one of the first hat-stringer sidewall or the hat-stringer connecting wall, or extending through at least one of the second hat-stringer sidewall (116) or the hat-stringer connecting wall. The ventilation opening defines a ventilation-opening centerline, wherein the ventilation-opening centerline does not coincide with the virtual hat-stringer-connecting-wall symmetry plane.

Abstract: A hat-stringer assembly (100) for an aircraft (500) comprises a hat stringer (110) with a first hat-stringer leg (140), a second hat-stringer leg (150), a first hat-stringer sidewall (114), a connecting wall (112), a second hat-stringer sidewall (116), and a ventilation opening (128), extending through the connecting wall (112). The hat stringer assembly (100) also comprises a fitting (200), comprising a first channel member (210) in contact with the first hat-stringer sidewall (114) and the first hat-stringer leg (140). The fitting (200) also comprises a second channel member (240) in contact with the second hat-stringer sidewall (116) and the second hat-stringer leg (150). The fitting (200) further comprises a web cap (260), in contact with the first channel member (210) and the second channel member (240). The web cap (260) comprises a web-cap opening (262), which is in fluidic communication with the ventilation opening (128).

Abstract: An aircraft includes a wing and a wing box. The wing is joined to the wing box at a side of body joint. The wing and the wing box each includes lower skin and a plurality of stringers on the skin. Ends of at least some of the stringers at the side of body joint have a web cutout and a base that is spanwise tapered to a knife edge at the skin.

Abstract: Structures and methods for joining composite fuselage sections and other panel assemblies together are disclosed herein. In one embodiment, a shell structure configured in accordance with the present invention includes a first panel portion positioned adjacent to a second panel portion. The first panel portion can include a first stiffener attached to a first composite skin, and the second panel portion can include a second stiffener attached to a second composite skin. The shell structure can further include a fitting extending across a first edge region of the first panel portion and a second edge region of the second panel portion. A first end portion of the fitting can be attached to the first stiffener and the first composite skin, and a second end portion of the fitting can be attached to a second stiffener and a second composite skin, to join the first panel portion to the second panel portion.

Abstract: A stringer beam joint structure of an aircraft formed from fiber-reinforced composites includes a wing and a wing box. The wing is joined to the wing box at a side of a joint structure. The wing and the wing box each includes a lower skin. A plurality of stringers is coupled to the lower skin and all made of fiber-reinforced composites. A first end of at least one of the plurality of stringers at the side of the joint structure features a web cutout with a taper formed in the base flange that spans longitudinal to the respective stringer and the taper located at the end of each respective stringer, where the taper runs from a knife edge of a base flange of the respective stringer to a full height of the base flange. The tapered surface of the base flange is contiguous with an edge of the web cutout.

Abstract: Structures and methods for joining composite fuselage sections and other panel assemblies together are disclosed herein. In one embodiment, a shell structure configured in accordance with the present invention includes a first panel portion positioned adjacent to a second panel portion. The first panel portion can include a first stiffener attached to a first composite skin, and the second panel portion can include a second stiffener attached to a second composite skin. The shell structure can further include a fitting extending across a first edge region of the first panel portion and a second edge region of the second panel portion. A first end portion of the fitting can be attached to the first stiffener and the first composite skin, and a second end portion of the fitting can be attached to a second stiffener and a second composite skin, to join the first panel portion to the second panel portion.

Abstract: Structures and methods for joining composite fuselage sections and other panel assemblies together are disclosed herein. In one embodiment, a shell structure configured in accordance with the present invention includes a first panel portion positioned adjacent to a second panel portion. The first panel portion can include a first stiffener attached to a first composite skin, and the second panel portion can include a second stiffener attached to a second composite skin. The shell structure can further include a fitting extending across a first edge region of the first panel portion and a second edge region of the second panel portion. A first end portion of the fitting can be attached to the first stiffener and the first composite skin, and a second end portion of the fitting can be attached to a second stiffener and a second composite skin, to join the first panel portion to the second panel portion.

Abstract: An aircraft includes a wing and a wing box. The wing is joined to the wing box at a side of body joint. The wing and the wing box each includes lower skin and a plurality of stringers on the skin. Ends of at least some of the stringers at the side of body joint have a web cutout and a base that is spanwise tapered to a knife edge at the skin.

Abstract: Structures and methods for joining composite fuselage sections and other panel assemblies together are disclosed herein. In one embodiment, a shell structure configured in accordance with the present invention includes a first panel portion positioned adjacent to a second panel portion. The first panel portion can include a first stiffener attached to a first composite skin, and the second panel portion can include a second stiffener attached to a second composite skin. The shell structure can further include a fitting extending across a first edge region of the first panel portion and a second edge region of the second panel portion. A first end portion of the fitting can be attached to the first stiffener and the first composite skin, and a second end portion of the fitting can be attached to a second stiffener and a second composite skin, to join the first panel portion to the second panel portion.

Abstract: A closeout fitting for a hat stringer includes a cover that has a fitting surface. The fitting surface is substantially complementary to at least a portion of an outer surface of the hat stringer. The cover is configured to couple against the hat stringer outer surface. The cover also includes a first portion configured to extend across a gap defined in a cap portion of the hat stringer. The closeout fitting also includes an insert. The insert includes a first outer perimeter surface that is substantially complementary to at least a portion of an interior surface of a channel defined by the hat stringer. The insert is configured to couple against the channel interior surface proximate the hat stringer closeout portion. The insert and the cover are formed with a suitable stiffness to limit a deformation of the hat stringer proximate the closeout portion.

Abstract: A closeout fitting for a hat stringer includes a cover that has a fitting surface. The fitting surface is substantially complementary to at least a portion of an outer surface of the hat stringer. The cover is configured to couple against the hat stringer outer surface. The cover also includes a first portion configured to extend across a gap defined in a cap portion of the hat stringer. The closeout fitting also includes an insert. The insert includes a first outer perimeter surface that is substantially complementary to at least a portion of an interior surface of a channel defined by the hat stringer. The insert is configured to couple against the channel interior surface proximate the hat stringer closeout portion. The insert and the cover are formed with a suitable stiffness to limit a deformation of the hat stringer proximate the closeout portion.

Abstract: A method of installing a door in an access opening in a skin of an aircraft. A composite inner door panel is positioned against an inside face of the skin. A composite outer door panel is positioned against an outside face of the skin. A plurality of fasteners is installed through fastener openings in the composite outer door panel. The plurality of fasteners is tightened to form a chamfered interface between the skin and the composite outer door panel.

Abstract: An aircraft includes a wing and a wing box. The wing is joined to the wing box at a side of body joint. The wing and the wing box each includes lower skin and a plurality of stringers on the skin. Ends of at least some of the stringers at the side of body joint have a web cutout and a base that is spanwise tapered to a knife edge at the skin.

Abstract: Structures and methods for joining composite fuselage sections and other panel assemblies together. In one embodiment, a shell structure configured in accordance with the present invention includes a first panel portion positioned adjacent to a second panel portion. The first panel portion can include a first stiffener attached to a first composite skin, and the second panel portion can include a second stiffener attached to a second composite skin. The shell structure can further include a fitting extending across a first edge region of the first panel portion and a second edge region of the second panel portion. A first end portion of the fitting can be attached to the first stiffener and the first composite skin, and a second end portion of the fitting can be attached to a second stiffener and a second composite skin, to join the first panel portion to the second panel portion.

Abstract: Structures and methods for joining composite fuselage sections and other panel assemblies together are disclosed herein. In one embodiment, a shell structure configured in accordance with the present disclosure includes a first panel portion positioned adjacent to a second panel portion. The first panel portion can include a first stiffener attached to a first composite skin, and the second panel portion can include a second stiffener attached to a second composite skin. The shell structure can include a fitting extending across a first edge region of the first panel portion and a second edge region of the second panel portion. A first end portion of the fitting can be attached to the first stiffener and the first composite skin, and a second end portion of the fitting can be attached to a second stiffener and a second composite skin, to join the first panel portion to the second panel portion.

Abstract: Structures and methods for joining composite fuselage sections and other panel assemblies together are disclosed herein. In one embodiment, a shell structure configured in accordance with the present disclosure includes a first panel portion positioned adjacent to a second panel portion. The first panel portion can include a first stiffener attached to a first composite skin, and the second panel portion can include a second stiffener attached to a second composite skin. The shell structure can include a fitting extending across a first edge region of the first panel portion and a second edge region of the second panel portion. A first end portion of the fitting can be attached to the first stiffener and the first composite skin, and a second end portion of the fitting can be attached to a second stiffener and a second composite skin, to join the first panel portion to the second panel portion.

Abstract: A method of installing a door in an access opening in a skin of an aircraft. A composite inner door panel is positioned against an inside face of the skin. A composite outer door panel is positioned against an outside face of the skin. A plurality of fasteners is installed through fastener openings in the composite outer door panel. The plurality of fasteners is tightened to form a chamfered interface between the skin and the composite outer door panel.

Abstract: A door for an aircraft wing fuel tank access opening includes an outer impact resistant composite door panel, and an inner composite door panel. Double seals on the inner door panel prevent fuel leakage, and a chamfered outer edge on the outer door panel transfers a component of impact loads laterally into the wing skin to increase kinetic energy absorption.